Onebow, A fella out east takes old barns down, just as you suspected, and sells the wood. He gives the proceeds to The American Chestnut Foundation so they can fund research to restore blight resistant trees. Here in MO there is a chestnut relative known as the Ozark chinquapin. It is similar in many ways to the chestnut with only one nut instead of three being the easiest telltale. Maximum height differs too with American Chestnut reaching heights of 100 feet plus and Ozark chinquapins reaching 60 to 70 before the blight reached the Ozarks.
I am on the hunt for some Ozark chinquapin wood too. My hope is to make a bow from it as well. There is a foundation trying to restore them too. My hope is to raise awareness with these bows. Both trees were historically used for furniture, fiddles, dulcimers, and rot resistant uses like shingles, coffins, and siding. Perhaps that nostalgic sense will help efforts to restore both species to their former glory. There is still hope to make more bows from these amazing trees. Hopefully mine will not be the last.
If anyone wants information on either, simply PM me and I will be glad to pass along the websites.